Halogen-flame retardants have always been used in the laminate for printed circuit to achieve a flame retardant purpose. However, during combustion, the halogen-flame retardant not only emits a large amount of smoke but also smells badly, and produces highly corrosive gas of hydrogen halide. It is also reported in a literature that in recent years, the halogen-flame retardant will produce carcinogen such as dioxin and dibenzofuran when high-temperature pyrolysis and combustion occurs. Therefore, with the official enforcement of “Instructions on Waste Electrical and Electronic Equipment” and “Instructions on Restricted Use of Hazardous Substances in Electrical and Electronic Equipment” by European Union on Jul. 1, 2006, the development of halogen-free flame retardant-type laminate for printed circuit has become a focus of the industry.
Since electronic materials become lighter, thinner, shorter and smaller, lower loss and higher thermal reliability become the future direction, which requires the laminate to have not only higher Tg, but also better inter-laminar adhesive force and lower coefficient of thermal expansion.
Therefore, how to obtain a composition having a halogen-free flame retardant property, good inter-laminar adhesive force and low coefficient of thermal expansion as well as high heat-humidity resistance is an urgent technical problem to be solved in this field.